Looks like mptbase.c is using offsetof but trying to use %d instead of %zd 
when printing a warning.  Fix it up to reduce warnings when compiling on 
systems where size_t isn't 32 bits.  With this patch and Alex's earlier one 
to fix up some ACPI warnings applied, the sn2_defconfig target is error and 
warning free.

Signed-off-by: Jesse Barnes <jbarnes@sgi.com>

Thanks,
Jesse